Popis: |
Having discussed the general theory of discontinuous groups on 3-dimensional hyperbolic space, we shall start in this chapter with the first of several series of arithmetic examples of such groups. This chapter will also fix the notation concerning imaginary quadratic number fields to be used in the following chapters. For the usual facts about algebraic number theory we refer to Lang (1993), Hecke (1923) or Hasse (1964). A useful little table of class numbers and ideal class groups is contained in Cohn (1980). |